Note this program requires the use of a modem which can be con- figured to completely ignore the status of the RS232c Data Termi- nal Ready (DTR) status line. If your modem hangs up the tele- phone line when the DTR line is lost, MSVR will not function.

This is a brief synopsis of the purpose, configuration require- ments, and usage of NetBIOS Modem, by Chris Cox.

At this time, NetBIOS Modem is still under extensive development however, in its present form, it does fill a void in many local area networks: that of allowing more than one person to use a modem.

NetBIOS Modem relies on the communications capabilities afforded by any network which, either relies on, or at least supports (such as Novell's NetWare), the NetBIOS communications interface.

Unlike many of it's commercial counterparts, NetBIOS Modem does not create an interface which adhere's to any formal, or de facto IBM PC communications structure at this time. Hence, anyone who needs to use the modem MUST use the included terminal emulation program VTERM.EXE. It is anticipated that this will not be the case in the future, but for the time being, that's the way it is!

Please be warned, this package has only had limited testing on one network, so it is not impossible that there are additional bug's to those which will be described in appendix A of this document.

If you find any additional bug's, please report them to me either via CompuServe 72711,1775, or MCI Mail account "Christopher G. Cox".

As is standard with most software, by using this package, you agree to indemnify me against, and I specifically refuse to carry any liability from your, or anybody else's, use of this package or any part of it.

You may distribute this package freely, as long as NO CHARGE of any form is made, including duplication, etc. In addition, all files supplied in this package as listed on the following page must be included, and no additions or removals are allowed.

Files included in this package are as follows:

NMODEM.DOC This document.

MSVR.EXE The executable program which runs on the PC acting as the modem server.

VTERM.EXE The executable program which runs on the PC using the modem server (i.e. the user!).

VT$DIAL.DAT An optional ASCII file which contains the name and number of frequently called systems (Please note it is optional whether or not you use this file.)

The file VT$DIAL.DAT is a simple ASCII file which contains the name and telephone numbers of any services which you regularly call using the NetBIOS Modem. Use of this file is entirely optional. As it contains just ASCII data, you may create and edit it using any ASCII editor, including EDLIN. The format of this file will be described after the pre-usage configuration which follows on the next page...

The only file which has to be available to anyone who needs to use your modem is VTERM.EXE.

Conversely, the personal computer which is to function as the modem server only needs to have access to the file MSVR.EXE.

If you wish to make use of the dialing directory, ensure that you call VTERM from the directory in which VT$DIAL.DAT is stored. If you are using the NetBIOS Modem on a Novell NetWare network, and you place VT$DIAL.DAT in the SYS:PUBLIC directory, then it can be found by any user who has SYS:PUBLIC included in their search path AS LONG AS THAT USER's LOGGED DRIVE IS A NETWORK DRIVE, when they execute VTERM.

Only one user at a time can access any one modem. If another user is connected to the modem, then an error message will be sent to the second user, and the program will exit back to DOS. However, mode than one copy of MSVR can be run simultaneously as long as any additional copies operate at a different baud rate. Baud rates supported are 110, 300, 1200, 2400, 4800, 9600, 19.2k, 38.4k, & 57.6k baud. The program has only been tested up to 9600 baud at this time. The default baudrate, if not specified, is 2400, as with version 1.0.

Configuration requirements.

The current version of NetBIOS Modem requires the use of a PC dedicated to operation as a modem-server. Version 2.0 has been tested under DesqView 2.26 and operates successfully in a multi- tasking environment.

MSVR [port] [baud-rate] where [port] is a number between 1 and 4. The default value is 1 for COM1:. and [baud-rate] is one of 110, 300, 1200, 2400, 4800, 9600, 19200, 38400, 57600. The default value is 2400.

Please note that MSVR should be run before running VTERM. If MSVR has not been run, or there is not a server available at the specified baud-rate, VTERM will fail and give an error message.

Usage of VTERM is even easier. It has only one optional parame- ter which may be used to specify the baudrate. To use a baud- rate other than 2400, MSVR must be run with the alternative baud- rate specified. If no baud-rate is supplied, 2400 will be used.

VTERM [baud-rate]

and you're on your way.

Dialing directory.

As stated before the format of the dialing directory is very simple. Each entry in the directory consists of a NAME and a NUMBER. That's it. Nothing more, nothing less. Please note, however, if you do create a dialing directory, it must have the entry LAST following the final directory entry, and there can be no more than 20 (twenty) entries in the directory.

Version 2.0 adds the capability to send and receive files using the XModem & YModem (1k-XModem) protocols. YModem BATCH is not supported in version 2.0.

XModem & YModem facilitate the transmission and reception of files with their inherrent error checking protocols. The file transfer feature is activated by pressing the function key. You will see a window popup on your screen asking you to enter four items.

The first is the name of the file which you want to send or receive. You may enter upto 64 characters into this field, allowing for the files full pathname. If you leave this field blank, pressing ESCAPE will return you to the terminal emulator.

Two of the other fields have default values assigned to them. One of these fields is used to select X or YModem - the default is XModem. The other is used to specify NAK or CRC XModem. This option defaults to CRC, which is a significantly better error checking method than the original NAK form of XModem. YModem always uses CRC, irrespective of the method you select.

The fourth field you must specify is for Upload or Download. There is no default value for this field, so you must choose either U or D.

Once you have filled in the necessary fields, press the ESCAPE key to initiate the file transfer.

Remember, if you want to leave the file transfer mode without sending or receiving a file, leave the filename field blank, and press ESCAPE.

Appendices.

Appendix A - Known bugs.

The bug that caused characters to be dropped has been eliminated, by dropping the DTR status line when sending a packet to the user running VTERM. This now requires that your modem ignore the status of the DTR line.

*** FIXED *** So far, there's only one known bug, and it's more of a nuisance than a problem! The problem is that occasion- ally (about once every two of three screensful of text) a character will get printed twice, or alternatively, a character will get dropped.

By monitoring the screen on the modem server, it can be seen that for some reason this character is actually appearing twice in, or being dropped from, the RS232 input buffer. This does not occur with other programs which use the same C asynchronous communications li- brary, and so appears to be caused intermittently by the NetBIOS calls. This is undergoing further examina- tion.